RF communications device with conductive trace and related switching circuits and methods

ABSTRACT

An RF communications device may include a circuit board having a dielectric layer and conductive traces, one of the conductive traces defining a transmission line. The RF communications device may also include an RF transmitter carried by the circuit board and coupled to the transmission line, and RF switching circuits, each RF switching circuit including a substrate having a tapered proximal end coupled to the transmission line, and a distal end extending outwardly on the convex side of the transmission line. Each RF switching circuit may include a series diode, and a shunt diode coupled to the series diode, the series diode extending from the tapered proximal end and across an interior of the substrate.

TECHNICAL FIELD

The present disclosure relates to the field of communications devices,and, more particularly, to RF communications devices with RF switchingcircuits and related methods.

BACKGROUND

Wireless communications devices are an integral part of society andpermeate daily life. The typical wireless communications device includesan antenna, and a transceiver coupled to the antenna. The transceiverand the antenna cooperate to transmit and receive communicationssignals. A typical radio frequency (RF) transceiver includes a poweramplifier for amplifying low amplitude signals for transmission via theantenna.

In some communications devices, the RF transceiver operates at multiplefrequency bands, i.e. a multi-band communications device. Accordingly,the multi-band communications device may include a switch between theantenna and the RF transceiver for routing the appropriate signalthrough frequency band specific circuitry, such as power amplifiers andfilters. In certain high power applications, diode switches may be usedfor the switch. In one approach, the diode switches comprise PIN (i.e. adiode with a wide, undoped intrinsic semiconductor region between ap-type semiconductor and an n-type semiconductor region) diodes in aseries-shunt configuration.

A series-shunt configuration of PIN diode switches is typically used toachieve a relatively high isolation, which may be important in highfrequency applications, for example greater than 1 GHz. To achieverelatively high isolation in the high power application, for example,greater than 10 W, a relatively high reverse bias voltage is used. Theseries diode and shunt diode of a particular switched path must beforward and reversed biased complementarily to minimize insertion lossand maximize isolation. Packaged series-shunt PIN diode switches mayprovide increased thermal performance and higher isolation.

SUMMARY

Generally speaking, an RF communications device may include a circuitboard comprising at least one dielectric layer and a plurality ofconductive traces thereon. One of the plurality of conductive traces maydefine a transmission line. The RF communications device may alsoinclude an RF transmitter carried by the circuit board and coupled tothe transmission line, and a plurality of RF switching circuits. Each RFswitching circuit may comprise a substrate having a tapered proximal endcoupled to the transmission line, and a distal end extending outwardlyfrom the transmission line. Each RF switching circuit may include aseries diode, and a shunt diode coupled to the series diode, the seriesdiode extending from the tapered proximal end and across an interior ofsaid substrate. Advantageously, the arrangement of the plurality of RFswitching circuits may reduce loss in the transmission line.

In some embodiments, each RF switching circuit is one oftriangle-shaped, or rhomboid-shaped. In another embodiment, the proximalends of the plurality of RF switching circuits are triangle-shaped, andthe distal ends of the plurality of RF switching circuits arerectangle-shaped. Additionally, the RF communications device may furthercomprise an antenna coupled to the distal ends of the plurality of RFswitching circuits. Each RF switching circuit may be discretelypackaged.

The shunt diode may comprise a PIN shunt diode, and the series diode maycomprise a PIN series diode. Also, the plurality of RF switchingcircuits may be coupled to the transmission line in order of increasingoperational frequency.

Another aspect is directed to an RF switching circuit for acommunications device. The RF switching circuit may include arhomboid-shaped substrate, and RF switching circuitry carried by therhomboid-shaped substrate and to be coupled between an RF transmitter inthe communications device and a transmission line in the communicationsdevice. The rhomboid-shaped substrate may have a tapered proximal end tobe coupled to the transmission line, and a distal end extendingoutwardly from the transmission line.

Yet another aspect is directed to an RF switching circuit for acommunications device. The RF switching circuit may include atriangle-shaped substrate, and RF switching circuitry carried by thetriangle-shaped substrate and to be coupled between an RF transmitter inthe communications device and a transmission line in the communicationsdevice. The triangle-shaped substrate may have a tapered proximal end tobe coupled to the transmission line, and a distal end extendingoutwardly from the transmission line.

Another aspect is directed to an RF switching circuit for acommunications device. The RF switching circuit may include substrate,and RF switching circuitry carried by the substrate and to be coupledbetween an RF transmitter in the communications device and atransmission line in the communications device. The substrate may have atriangle-shaped proximal end to be coupled to the transmission line, anda rectangle-shaped distal end extending outwardly from the transmissionline.

Another aspect is directed to a circuit device. The circuit device mayinclude a rhomboid-shaped substrate, and circuitry carried by therhomboid-shaped substrate and to be coupled between a first circuit anda second circuit. The rhomboid-shaped substrate may have a taperedproximal end to be coupled to the second circuit, and a distal endextending outwardly from the second circuit.

Another aspect is directed to a circuit device. The circuit device mayinclude a substrate, and circuitry carried by the substrate and to becoupled between a first circuit and a second circuit. The substrate mayhave a triangle-shaped proximal end to be coupled to the second circuit,and a rectangle-shaped distal end extending outwardly from the secondcircuit.

Another aspect is directed to a method of making an RF communicationsdevice. The method may include forming a circuit board comprising atleast one dielectric layer and a plurality of conductive traces thereon,one of the plurality of conductive traces defining a transmission line,and forming an RF transmitter on the circuit board and coupled to thetransmission line. The method may further comprise forming a pluralityof RF switching circuits, each RF switching circuit comprising asubstrate having a tapered proximal end coupled to the transmissionline, and a distal end extending outwardly from the transmission line.Each RF switching circuit may include a series diode, and a shunt diodecoupled to the series diode, the series diode extending from the taperedproximal end and across an interior of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an RF communications device, accordingto the present disclosure.

FIGS. 2A and 2B are respectively a schematic circuit diagram and aschematic packaging diagram of an embodiment of the RF switching circuitfrom the RF communications device of FIG. 1.

FIG. 2C is a schematic diagram of an embodiment of RF switching circuitscoupled to a launch trace from the RF communications device of FIG. 1.

FIG. 3 is a detailed schematic diagram of another embodiment of the RFswitching circuit, according to the present disclosure.

FIGS. 4A and 4B are respectively a schematic diagram and a schematicpackaging diagram of another embodiment of the RF switching circuit,according to the present disclosure.

FIG. 5 is a schematic diagram of several RF switching circuits fromFIGS. 4A-4B coupled to a launch trace.

FIGS. 6A and 6B are respectively a schematic diagram and a schematicpackaging diagram of yet another embodiment of the RF switching circuit,according to the present disclosure.

FIG. 7 is a schematic diagram of several RF switching circuits fromFIGS. 6A-6B coupled to a launch trace.

FIG. 8 is a schematic diagram of the RF switching circuits of FIGS.6A-6B during manufacture.

FIG. 9A is a schematic diagram of another embodiment of the RF switchingcircuit, according to the present disclosure.

FIG. 9B is a schematic diagram of several RF switching circuits fromFIG. 9A coupled to a launch trace.

FIGS. 10A and 10B are respectively a schematic diagram and a schematicpackaging diagram of another embodiment of the RF switching circuit,according to the present disclosure.

FIG. 11 is a schematic diagram of several RF switching circuits fromFIGS. 10A-10B coupled to a launch trace.

FIG. 12 is a schematic diagram of the RF switching circuits of FIGS.10A-10B during manufacture.

FIG. 13 is a schematic diagram of several RF switching circuits fromFIGS. 10A-10B coupled to another embodiment of the launch trace.

FIG. 14 is a schematic diagram of several RF switching circuits fromFIGS. 9A-9B coupled to another embodiment of the launch trace.

FIG. 15 is a modeling diagram of several RF switching circuits coupledto the launch trace, according to the present disclosure.

DETAILED DESCRIPTION

The present disclosure will now be described more fully hereinafter withreference to the accompanying drawings, in which several embodiments ofthe invention are shown. This present disclosure may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein. Rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the present disclosure to those skilled in theart. Like numbers refer to like elements throughout, and base 100reference numerals are used to indicate similar elements in alternativeembodiments.

Referring initially to FIGS. 1-2C, an RF communications device 20according to the present disclosure is now described. The RFcommunications device 20 illustratively includes a circuit board 21comprising one or more dielectric layers and a plurality of conductivetraces 24-25 on the dielectric layer. In the illustrated embodiment, oneof the plurality of conductive traces 24-25 has a curved shape defininga transmission line (i.e. a launch, launch pad, or a curved launchtrace) 24 with a convex side and a concave side.

The RF communications device 20 illustratively includes an RFtransmitter (e.g. an RF transceiver) 23 carried by the circuit board 21and coupled to the transmission line 24, and a plurality of RF switchingcircuits 26 a-26 g. Each RF switching circuit 26 a-26 g illustrativelyincludes a tapered proximal end 44 coupled to the transmission line 24,and a distal end 45 extending outwardly on the convex side of thetransmission line. Each RF switching circuit 26-26 g may be discretelypackaged.

In the illustrated embodiment, each RF switching circuit 26 a-26 g isrectangle-shaped. In other embodiments, the plurality of RF switchingcircuits 26 a-26 g may each be triangle-shaped (FIGS. 10A-12) orrhomboid-shaped (FIGS. 6A-9B). It should be appreciated that even othershapes can be used. Additionally, the RF communications device 20illustratively includes an antenna 22 coupled to the distal ends 45 ofthe plurality of RF switching circuits 26 a-26 g. In some embodiments,such as the illustrated embodiment, the antenna 22 is carried by thecircuit board 21, but in other embodiments, the antenna is carriedoff-chip.

The RF communications device 20 illustratively includes a plurality oftransmission chains (e.g. band pass filters, power amplifiers, etc.) 81a-81 g carried by the circuit board 21 and coupled respectively to theRF switching circuits 26 a-26 g. Also, the RF communications device 20illustratively includes an RF combiner 82 carried by the circuit board21 and coupled between the antenna 22 and the plurality of transmissionchains 81 a-81 g.

As best seen in FIG. 2A, each RF switching circuit 26 a-26 gillustratively includes a substrate 43, a series diode 27 carried by thesubstrate, a shunt diode 28 carried by the substrate and coupled to theseries diode, and a capacitor 29 carried by the substrate and coupled tothe shunt diode. The series diode 27 extends (i.e. the series diode andthe conductive traces coupling the cathode and anode of the seriesdidoe) from the tapered proximal end 44 and in an opposite direction(i.e. towards the opposing corner and diagonally across therectangle-shaped RF substrate 43. In particular, the series diode 27extends along a line that substantially bisects (i.e. leaving 40-50% oneach side) an angle defined by the tapered proximal end 44. In otherwords, the series diode 27 extends across an interior of the substrate43. In some embodiments, the shunt diode 28 may comprise a PIN shuntdiode, and the series diode 27 may comprise a PIN series diode, definingRF switching circuitry 27-29. Advantageously, the output line from acathode of the series diode 27 extends diagonally across the substrate43, extending between diagonal corners of the substrate. This diagonalarrangement permits the tapered proximal ends 44 of the plurality of RFswitching circuits 26-26 g to be coupled to the transmission line 24.

Also, with additional reference to diagram 700 of FIG. 15, in someembodiments, the plurality of RF switching circuits 26 a-26 g may becoupled to the transmission line 24, 724 in order of increasingoperational frequency. In other words, the diodes are arranged in order(or roughly in order) from lowest frequency to highest frequency, i.e.770 a, 771, 770 b, 770 c, & 770 d (if they represent switches betweenpaths that cover different frequency bands such as a bank of filters).

Helpfully, this may ensure that the highest frequency band will be atthe distal end of the transmission line 24, 724 and will have theshortest open circuit stub, which allows for broadest band operation.The longest stub likely does not represent a problem at the lowestfrequency band. In diagram 700, the second lowest frequency diode 771 ison, transmitting through portion TL1 and leaving an open circuitportion/stub TL3.

It should be appreciated that the transmission line 24, 724 is modeledas an infinite chain of series inductances and shunt capacitances. Thereversed biased shunt diodes 770 a-770 d (i.e. off state) are modeled bya shunt capacitance, which is undesired. In the present disclosure,these shunt capacitances are advantageously absorbed along thetransmission line 24, 724. Also, the transmission line 24, 724 width canbe selected to maintain the desired impedance.

The capacitor 29 does not need to have a total needed capacitance, butonly needs to have enough capacitance to provide high-frequencyisolation where package parasitic effects would prohibit goodperformance. The rest of the capacitance needed for low-frequencyisolation is accomplished with an off-chip capacitor. Approximately 10pF on-chip (capacitor 29) and 100 pF to 1000 pF off-chip would besufficient depending on frequencies of operation. Helpfully, thecapacitor 29 is part of an integrated package and improves highfrequency performance while allowing for proper selection of an externallow frequency capacitor. Although not shown, the low frequency capacitorwould be coupled to a node between the shunt diode 28 and the capacitor29. Also, by integrating the series and shunt diodes 27-28 into acommon, heat-sunk package, the RF switching circuit 26 a-26 g hasimproved isolation and power handling, as well as reduced size andcomplexity.

It should be appreciated that the RF switching circuitry 27-29embodiment illustrated herein is exemplary. Other known PIN diode switchconfigurations may be used.

As best seen in FIG. 2B, each RF switching circuit 26 a-26 gillustratively includes an RF input node 32 coupled to an anode of theseries diode 27, a bias node 30 coupled to a node between the capacitor29 and the shunt diode 28. Also, each RF switching circuit 26 a-26 gillustratively includes an RF output node 31 coupled between the seriesdiode 27 and the shunt diode 28, and a ground plane 33. It should beappreciated that the nodes 30-32 are illustratively rectangle-shaped,but could also be oval-shaped or circle-shaped.

Another aspect is directed to a method of making an RF communicationsdevice 20. The method includes forming a circuit board 21 comprising oneor more dielectric layer and a plurality of conductive traces 24-25thereon. One of the plurality of conductive traces 24-25 has a curvedshape defining a transmission line 24 with a convex side and a concaveside. The method includes forming an RF transmitter 23 on the circuitboard 21 and coupled to the transmission line 24. The method furthercomprises forming a plurality of RF switching circuits 26 a-26 g, eachRF switching circuit having a tapered proximal end 44 coupled to thetransmission line 24, and a distal end 45 extending outwardly on theconvex side of the transmission line.

Referring now additionally to FIG. 3, an example embodiment of the RFcommunications device 20 is now described. The RF communications device20 illustratively includes a second capacitor 36 coupled to the outputnode 31 of the RF switching circuit 26, and a band pass filter 35coupled between the second capacitor and an RF out (i.e. the antenna22). The RF communications device 20 illustratively includes a firstinductor 38 coupled to the output node 31 of the RF switching circuit26, and a high voltage driver 37 coupled to the first inductor. The RFcommunications device 20 illustratively includes a third capacitor 41coupled to an RF input node (i.e. an output of the RF transmitter 23), asecond inductor 39 coupled to the third capacitor, and a first resistor40 coupled to the first inductor. Also, the RF communications device 20illustratively includes a second resistor 34 coupled to the bias node 30of the RF switching circuit 26. As will be appreciated, the output fromthe output of the RF transmitter 23 branches out into three outputbranches, each for a respective transmission frequency band.

In typical approaches to multi-band RF devices, there is a desire toselectively switch high power RF signals through multiple filter banks.A typical approach to this technical desire was to use PIN diodeswitches in series-shunt configuration to control routing of the highpower RF signals. When designing the PIN diode switches, there aredesign trade-offs to be made in terms of three performance parameters:insertion loss (affects overall system power consumption); isolation(affects cosite, harmonics and spurious performance); and power handlingcapability (affects reliability). In some existing approaches, the PINdiode switches are either discrete approaches or packaged (multi-throw)approaches.

With discrete approaches, although quite flexibly configured andreconfigured, these approaches may have long launch paths (highinsertion loss), and series diodes are poorly heat sunk and have highoperating temperatures. Also, these discrete approaches suffer frompackage parasitic and length between series and shunt diodes, whichreduce isolation performance, and suffer from high part counts, whichmay be difficult to layout and launch. Indeed, discrete approaches maysuffer from poor performance at operational frequencies greater than 1GHz and operational power modes greater than 5 W.

With packaged multi-throw approaches, the diode switches are thermallystrong, have improved isolation, and have small launches. Nevertheless,these packaged approaches may suffer from the following issues: sinceeach packaged diode switch device is quite inflexible, users typicallyneed to source several different types of packaged multi-throw devices,which increases cost and lead times for design, and packaged diodeswitch devices are more expensive than discrete devices. Also, ascustomers change operational frequency bands, the inflexibility ofpackaged approaches may require substantial redesigns.

Advantageously, the plurality of RF switching circuits 26 a-26 g of theRF communications device 20 provides integrated series-shunt PIN diodeswitches with improved isolation, improved and rugged thermalperformance, and fewer parts. Also, the plurality of RF switchingcircuits 26 a-26 g consumes less board space than in typical discreteapproaches. Also, using the RF switching circuits 26 a-26 g as a switchbuilding block, more complex switches can readily be assembled. Forexample, you can build an N-throw (SPnT) switch, or even (mPnT) switch.Indeed, the RF switching circuits 26 a-26 g are tesselated to enhancepackage density.

The compact shapes and corner pads of the plurality of RF switchingcircuits 26 a-26 g may allow for very tight optimal launches of highfrequency operation. This is accomplished by shortening the length andassociated loss of the transmission line 24. The reason minimizing thelength of the transmission line 24 for all of the RF switching circuits26 a-26 g is important is because the length of transmission line pastthe ON diode is an open-circuited stub. At some high frequency, thisopen circuit stub will look like a short circuit, and as you approachthat frequency, the insertion loss of the switch will be degraded.

The disclosed RF switching circuit 26 a-26 g may allow for easyreconfiguration, but also with improved isolation. In essence, the RFswitching circuit 26 a-26 g may afford the benefits of both the discreteapproaches and the packaged approaches without the respective negatives.

Referring now additionally to FIGS. 4A-5, another embodiment of the RFcommunications device 420 is now described. In this embodiment of the RFcommunications device 420, those elements already discussed above withrespect to FIGS. 1-3 are incremented by 400 and most require no furtherdiscussion herein. This embodiment differs from the previous embodimentin that this RF communications device 420 illustratively includes an RFswitching circuit 426 a-426 g comprising a substrate 443, and RFswitching circuitry 427-429 carried by the substrate and to be coupledbetween an RF transmitter 423 in the communications device 420 and atransmission line 424 in the communications device. The transmissionline 424 has a convex side and a concave side. The substrate 443 has atriangle-shaped proximal end 444 to be coupled to the transmission line424, and a rectangle-shaped distal end 445 extending outwardly on theconvex side of the transmission line 424. In other words, the substrate443 is “home plate-shaped”. In other words, the substrate 443 is afive-sided polygon, i.e. a pentagon. The RF switching circuitry 427-429extends from a vertex of the triangle-shaped proximal end 444 to amidpoint of a side of the rectangle-shaped distal end 445.

Referring now additionally to FIGS. 6A-8, another embodiment of the RFcommunications device 120 is now described. In this embodiment of the RFcommunications device 120, those elements already discussed above withrespect to FIGS. 1-3 are incremented by 100 and most require no furtherdiscussion herein. This embodiment differs from the previous embodimentin that this RF communications device 120 illustratively includes an RFswitching circuit 126 a-126 g comprising a rhomboid-shaped (i.e.parallelogram-shaped or diamond-shaped) substrate 143, and RF switchingcircuitry 127-129 carried by the rhomboid-shaped substrate and to becoupled between an RF transmitter 123 in the communications device and atransmission line 124 in the communications device. The transmissionline 124 has a convex side and a concave side. The rhomboid-shapedsubstrate 143 illustratively includes a tapered (i.e. triangle-shaped)proximal end 144 to be coupled to the transmission line 124, and adistal end (i.e. triangle-shaped) 145 extending outwardly on the convexside of the transmission line. The RF switching circuitry 127-129extends from a vertex of the triangle-shaped proximal end 144 to anopposing vertex the triangle-shaped distal end 145.

In FIG. 8, during manufacturing of the RF switching circuits 126 a-126g, the rhomboid-shaped substrate 143 may be readily formed in bulk via amulti-step dicing process from a wafer 142. Advantageously, themulti-step dicing process may use only two dicing directions.

Referring now additionally to FIGS. 9A-9B, another embodiment of the RFcommunications device 220 is now described. In this embodiment of the RFcommunications device 220, those elements already discussed above withrespect to FIGS. 1-3 are incremented by 200 and most require no furtherdiscussion herein. This embodiment differs from the previous embodimentin that this RF communications device 220 illustratively has each RFswitching circuit 226 a-226 g comprising a single pole-double throwswitch (SP2T). Each RF switching circuit 226 a-226 g comprises first andsecond series diodes 227 a-227 b, first and second shunt diodes 228a-228 b coupled respectively to the first and second series diodes, andfirst and second capacitors 229 a-229 b coupled respectively to thefirst and second shunt diodes. In this embodiment, the transmission line224 is C-shaped (i.e. a partial hairpin shape).

Although the other embodiments are illustrated with single pole-singlethrow (SPST) arrangements, the SP2T switch can be employed in any of theother embodiments/shapes disclosed herein. With SPSTs and SP2Ts, anyswitch configuration could be made with a very small size and compactlaunch. While extending these shapes past SP2T would be possible,combining SPSTs and SP2Ts makes it unnecessary. In some embodiments,only SP2Ts could be used as well. If the desired number of switch pathsis odd, one port of an SP2T could be left unused.

Referring now additionally to FIGS. 10A-12, another embodiment of the RFcommunications device 320 is now described. In this embodiment of the RFcommunications device 320, those elements already discussed above withrespect to FIGS. 1-3 are incremented by 300 and most require no furtherdiscussion herein. This embodiment differs from the previous embodimentin that this RF communications device 320 illustratively includes an RFswitching circuit 326 a-326 g comprising a triangle-shaped substrate343, and RF switching circuitry 327-329 carried by the triangle-shapedsubstrate and to be coupled between an RF transmitter 323 in thecommunications device and a transmission line 324 in the communicationsdevice. The transmission line 324 has a convex side and a concave side.

The triangle-shaped substrate 343 illustratively includes a taperedproximal end 344 to be coupled to the transmission line 324, and adistal end 345 extending outwardly on the convex side of thetransmission line. The RF switching circuitry 327-329 extends betweenvertexes of the triangle-shaped substrate 343. In this embodiment, thetransmission line 324 is candy-cane shaped or partial loop-shaped.

In FIG. 12, during manufacturing of the RF switching circuits 326 a-326g, the triangle-shaped substrate 343 may be readily formed in bulk via amulti-step dicing process from a wafer 342. Advantageously, themulti-step dicing process may use only three dicing directions.

Referring now additionally to FIG. 13, another embodiment of thetransmission line 524 and RF switching circuits 526 a-526 g is nowdescribed. In this embodiment of the transmission line 524 and RFswitching circuits 526 a-526 g, those elements already discussed abovewith respect to FIGS. 1-3 are incremented by 500 and most require nofurther discussion herein. This embodiment differs from the previousembodiment in that this transmission line 524 is straight and the RFswitching circuits 526 a-526 g are triangle-shaped (FIGS. 10A-10B).

Referring now additionally to FIG. 14, another embodiment of thetransmission line 624 and RF switching circuits 626 a-626 f is nowdescribed. In this embodiment of the transmission line 624 and RFswitching circuits 626 a-626 f, those elements already discussed abovewith respect to FIGS. 1-3 are incremented by 500 and most require nofurther discussion herein. This embodiment differs from the previousembodiment in that this transmission line 624 is L-shaped (i.e.intersecting straight lines at near/substantial right angles, range85°-95°) and the RF switching circuits 626 a-626 g are diamond-shaped(FIGS. 6A-6B).

It should be appreciated that the above substrate shapes for RFswitching circuits 26 a-26 g, 426 a-426 g, 126 a-126 g, 226 a-226 d, 326a-326 g, 526 a-526 g, 626 a-626 f can be applied to other non-RFswitching circuit types. For example, these other circuit types includecircuit devices with generic circuitry, bias tees, feed chokes,detectors, Electrostatic discharge (ESD) protection, low temperatureco-fired ceramic (LTCC) filters, power dividers, resistive taps, andvaractor diodes.

Other features relating to RF communications devices are disclosed inco-pending application titled “SWITCHING CIRCUIT INCLUDING DC-DCCONVERTER COOPERATING WITH A HIGH VOLTAGE SUPPLY AND RELATED METHODS”,U.S. patent application Ser. No. 14/451,957, which is incorporatedherein by reference in its entirety.

Many modifications and other embodiments of the present disclosure willcome to the mind of one skilled in the art having the benefit of theteachings presented in the foregoing descriptions and the associateddrawings. Therefore, it is understood that the present disclosure is notto be limited to the specific embodiments disclosed, and thatmodifications and embodiments are intended to be included within thescope of the appended claims.

That which is claimed is:
 1. A radio frequency (RF) communicationsdevice comprising: a circuit board comprising at least one dielectriclayer and a plurality of conductive traces thereon, one of saidplurality of conductive traces defining a transmission line; an RFtransmitter carried by said circuit board and coupled to saidtransmission line; and a plurality of rectangle-shaped RF switchingcircuits, each rectangle-shaped RF switching circuit comprising asubstrate having a tapered proximal end coupled to said transmissionline, and a distal end diagonally opposite the tapered proximal end andextending outwardly from said transmission line; each rectangle-shapedRF switching circuit comprising a series diode, and a shunt diodecoupled to said series diode, said series diode extending diagonallyacross an interior of said substrate and having an input at the taperedproximal end and an output at the distal end.
 2. The RF communicationsdevice of claim 1 further comprising an antenna coupled to the distalends of said plurality of rectangle-shaped RF switching circuits.
 3. TheRF communications device of claim 1 wherein each rectangle-shaped RFswitching circuit is discretely packaged.
 4. The RF communicationsdevice of claim 1 wherein said shunt diode comprises a PIN shunt diode;and wherein said series diode comprises a PIN series diode.
 5. The RFcommunications device of claim 1 wherein said plurality ofrectangle-shaped RF switching circuits are coupled to the transmissionline in order of increasing operational frequency.
 6. A radio frequency(RF) switching circuit for a communications device, the RF switchingdevice comprising: a rectangle-shaped substrate; and RF switchingcircuitry carried by said rectangle-shaped substrate and to be coupledbetween an RF transmitter in the communications device and atransmission line in the communications device; said rectangle-shapedsubstrate having a tapered proximal end to be coupled to thetransmission line, and a distal end diagonally opposite the taperedproximal end and extending outwardly from the transmission line; said RFswitching circuit comprising a series diode, and a shunt diode coupledto the series diode, the series diode extending diagonally across aninterior of the rectangle-shaped substrate and having an input at thetapered proximal end and an output at the distal end.
 7. The RFswitching circuit of claim 6 wherein the distal end of saidrectangle-shaped substrate is to be coupled to an antenna of thecommunications device.
 8. The RF switching circuit of claim 6 whereinsaid shunt diode comprises a PIN shunt diode; and wherein said seriesdiode comprises a PIN series diode.
 9. A method of making a radiofrequency (RF) communications device, the method comprising: forming acircuit board comprising at least one dielectric layer and a pluralityof conductive traces thereon, one of the plurality of conductive tracesdefining a transmission line; forming an RF transmitter on the circuitboard and coupled to the transmission line; and forming a plurality ofrectangle-shaped RF switching circuits, each rectangle-shaped RFswitching circuit comprising a substrate having a tapered proximal endcoupled to the transmission line, and a distal end diagonally oppositethe tapered proximal end and extending outwardly from the transmissionline, each rectangle-shaped RF switching circuit comprising a seriesdiode, and a shunt diode coupled to the series diode, the series diodeextending diagonally across an interior of the substrate and having aninput at the tapered proximal end and an output at the distal end. 10.The method of claim 9 further comprising coupling an antenna to thedistal ends of the plurality of rectangle-shaped RF switching circuits.11. The method of claim 9 wherein each rectangle-shaped RF switchingcircuit is discretely packaged.
 12. The method of claim 9 wherein theshunt diode comprises a PIN shunt diode; and wherein the series diodecomprises a PIN series diode.
 13. The method of claim 9 furthercomprising coupling the plurality of rectangle-shaped RF switchingcircuits to the transmission line in order of increasing operationalfrequency.